Advanced Materials Research Vols. 594-597

Abstract: As the carrier of all kinds of study & engineering, the data as well as its quality have always been the focus concerned popularly. With the original source analysis as the beginning, the paper analyzes the relationship between the objective world and the data, as well as the sources of the scientific data uncertainty. Then the intrinsic property of the scientific data was also introduced, followed by the introduction of the relationship between data management and GIS(Geographic Information System). After that, several normal methods to evaluate & manage data were put forward, followed by a summary. And this would be interesting for deeply study of the related fields.

Abstract: To meet the requirements of emergency evacuation in a large hotel, this paper introduces design and implementation of emergency evacuation simulation model for a large hotel based on GIS in detail. Firstly, the design of the simulation model is introduced in the paper. Four-tier framework of the model is composed of user layer, application layer, underlying support layer and data layer. Secondly, the key technologies of the model are emphasized. The spatial analysis and attribute data analysis of GIS are used to determine evacuation zone of emergencies and disasters in a large hotel and achieve the optimal emergency evacuation plan for crowd. Finally, test results showed the model improves the simulation precision and can provide effective service for emergency evacuation in a large hotel.

Abstract: Airborne LiDAR (Light Detection and Ranging) is a powerful remote sensing measure to derive 3D coordinates from terrain surface. Automated or semi-automated road networks extraction from laser point clouds has been a challenging work during last few decades. In this paper, combining intensity with height information of point clouds, initial road point class is discerned using few seed points and subsequently smoothed throughout filling holes technology and morphological open operations. The skeleton of road networks is acquired by virtue of image thinning method and further eliminating short road burrs with length criteria. These center points of road are tracked and connected into vector line segments. By simplifying line nodes, road network can be formed in accuracy of which completeness is 79.8% and correctness is 79%. The virtues of this algorithm enables efficiently reduce errors brought by parking lots.

Abstract: There are heat-fluid-solid multi-field coupling in the thermal recovery reservoir. At present, the researches on oil reservoir porous media coupling are mostly on fluid-solid. According to the oil reservoir characteristics, this paper puts forward the “white box” analysis model on the heat and mass transfer processes in thermal recovery reservoir. On this basis, the analysis and stimulation of the various porosity effects on heat and mass transfer processes use CMG software. This result can provide theoretical basis for enhancing oil/gas recovery.

Abstract: For theoretical modeling of water flow and heat transfer processes in fractured rocks, one of the most commonly employed assumptions is that instantaneous local thermodynamic equilibrium exists between the water, the fills in the fractures, and the surfaces of the neighboring rock matrix blocks. An analysis of the effects of such assumption is conducted through semi-analytical calculations of heat transfer in a single fracture impermeable rock. It is observed that, for the heat exchange between water and fill, the ratio of the convective coefficient and the grain size acts as the major influencing factor to the validity of the instantaneous local thermal equilibrium between water and fill, that the discrepancies caused by using the thermal equilibrium for heat exchange between rock matrix and water can be significant at locations close to the heat source and at early times of the process, but reduce rather quickly to negligible levels as the distance to the heat source and the time increase, and that the influence of the thermal equilibrium assumption also becomes less significant if the water velocity is small, if the heat capacity and conductivity of rock matrix is small and the convection coefficient is large.

Abstract: In this paper, employing reservoir simulation and mathematical analysis methods, considering typical heavy oil reservoir and fluid thermal properties, the heating and producing shape of thermal recovery with horizontal well for different heavy oil reservoirs including ordinary, extra and super heavy oil are investigated based on the modification of thermal recovery parameters of different viscosity. By introducing heating radius and producing radius and considering the coupling effect of temperature, pressure and oil saturation fields, a quantitative expression between heating radius/producing radius and oil viscosity, formation thickness is presented, so is the impact of oil viscosity on the heating radius. Results shows that for Cyclic Steam Stimulation, the producing radius of horizontal well is bigger than its heating radius for light oil, both of which, however, shrink with higher viscosity. Beyond a critical viscosity, where the heating radius equals to the producing radius, the heating radius of horizontal well would be bigger than its producing radius. More over, the critical viscosity shows tight relationship to the formation thickness.

Abstract: Water injection is one of the important ways to maintain reservoir pressure and improving the oilfield development effect. And separate zone water injection is the main technology in water flooding oilfield. The optimal water intensity which has been allocated plays an important role in all kinds of reservoir. This paper proposed a method to optimize the water injection intensity based on oil production rate and water cut. Conceptual model was constructed on the basis of real reservoir. By numerical simulation, a chart board was derived which describes the relationship of water injection intensity versus oil production rate and water cut. Using this chart, we can determine the optimal water injection intensity on different oil production rate and water cut.

Abstract: This paper selects the Xietan sewage treatment plant slope as research object, used the fluid-solid coupling finite element analysis software (ABAQUS) and intelligent displacement back analysis method to dynamically inverse the deformation module of rock and soil of the slope when exposed to water level fluctuation. The results show that the calculation displacement values of measuring point which based on the inversion method is very close to that based on field measurement, which indicates the intelligent displacement back analysis method is suitable to dynamically inverse rock and soil physical and mechanical parameters of slope when exposed to reservoir water level fluctuation.

Abstract: CO₂ is inclined to dissolve in crude oil in the reservoir condition and accordingly bring the changes in the crude oil composition, which will induce asphaltene deposition and following formation damage. In this paper, core flooding device is applied to study the effect of asphaltene deposition on flooding efficiency. From the flooding results, dissolution of CO₂into oil leads to recovery increase because of crude oil viscosity reduction. But precipitated asphaltene particles may plug the pores and throats, which will make the flooding effects worse. Under the same experimental condition and with equivalent crude oil viscosity, the recovery of oil with higher proportion of precipitated asphaltene was relatively lower during the CO₂ flooding, so the asphltene precipitation would affect CO₂ displacement effici_{Subscript text}ency and total oil recovery to some extent. Combination of static diffusion and dynamic oil flooding would provide basic parameters for further study of the CO₂ flooding mechanism and theoretical evidence for design of CO₂ flooding programs and forecasting of asphaltene deposition.

Abstract: The uplift pressure on the foundation surface is one of the unfavorable factors for the stability of a gravity dam. The seepage/stress coupling character in the rock foundation may make the change of the seepage field which can lead to the change of the value of uplift pressure. In this paper, the seepage/stress coupling in fractured rock masses is studied by the two fields across iterative method with the help of block element method. A gravity dam is studied and the numerical analysis results show that the normal stress can affect the seepage character of rock masses greatly. In the region of high pressure stresses, the transmissivity deduces which can bring about the increment of gradient and velocity. This will bring an adverse impact on the stability of the dam. The coupling of seepage and stress in fractured rock foundation cannot be ignored in arithmetical analysis.